Improvement in trammels or beam-compasses



C. H. LATHROP.

Tramme'ls or Beam-Compasses.

Pat ented April 14, 1874..

No.l49,76l.

NI'IED STATES PATENT OFFICE.

GHANOY H. LATHROP, OF JERSEY CITY, ASSIGNOR OF PART OF HIS RIGHT TO ROBESON PATON, OF WORTENDYKE, NEW JERSEY.

IMPROVEMENT IN TRAMMELS OR BEAM-COMPASSES.

Specification forming part of Letters Patent No. 149,761, dated April 14,1874; application filed February 7,1874. W

To all whom it may concern:

Be it known that I, CHANOY H. LATHROP, of Jersey City, in the county of Hudson and State of New Jersey, have invented certain Improvements in Trammels, of which the following is a specification:

The invention consists in the novel combination of slides and cam-binders applied to the bar of a trammel, whereby the slides and cambinders form holders for the center-points, pencil, pencil-holder, tracer, pen, or other device applied to the trammel, and the cam-binders operate at the same time to serve the two purposes of securing the center-points,pencil,penoil-holder, tracer, pen, or other device or attachment in the slide, and of securing the slides to the bar.

In the accompanying drawing, Figure 1 is a side elevation of my improved trammel. Fig. 2 is a transverse section of the same. Fig. 3 is a top view of the same. Fig. 4 is a detail View of a pencil-holder and washer-cutter.

The bar A is made concavo-convex, in the .usual form, its orosssection resembling a hollow truncated cone.

The slide B is formed of a fiat bar or plate, with its ends bent at right angles, and perforated to receive the points or legs of the inetrument. The eccentric cambinder consists of 'a plate, 0, with perforated lugs 0 formed at two of its corners, which lugs are turned down at right angles with its surface, but in planes parallel with its longitudinal axis. The inner surfaces of the lugs are inclined or tapered outward, to correspond with the tapering sides of the bar. The slide is placed on the bar with its perforated ends or lugs extending beyond the outer or convex portion of the bar. The binder is placed with its lugs inside of or between those of the slide, and with all the perforations in line. The leg is then inserted in place by passing it through the perforations. The lugs 0 of the binder are perforated eccentrioally with relation to the inclined sides of the bar, and their inclined inner surfaces are not exactly parallel with those of the bar, so that when the main surface of the binder is parallel with the longitudinal axis of the bar, as shown in the drawing, the leg and slide are securely clamped and held in position; but when the main portion or thumb-piece c is turned outward at a right auglewith the surface of the bar, it loosens the parts, so as to allow the leg to be removed or the slide to bemoved to a different position. faces of the lugs 0 may be roughened or serrated, and a saddle, 61, may be'interposed between them and the bar, to prevent marring of the latter. The perforations in the slide are nearer to one edge than the other, so that, when the slides are in the positions with relation to each other shown inthe drawing, the legs or points maybe brought very close to each other; and when their positions are reversed, they may, if necessary, be extended beyond the extremities of the bar.

The legs used in this instrument may be of the ordinary form, or they may be provided with heads, to allow of the use of the instrument as a ball-gage.

Different legs may be provided to be used at pleasure, such as. a washer-cutter, pen or pencil holder, &c.; or a pencil may be inserted in place of a leg, if desired.

Fig. 1 of the drawing shows one of the legs formed with a head for use as a ball-gage, and Fig.4 shows a leg with a washer-cutter on one end and a pencil-holder on the other.

What I claim as new, and desire to secure by Letters Patent, is-

The combination of the slides and cam-binders with the bar and the center-points, pencil, pencil-holder, tracer, pen, or other devices or attachments, substantially as herein described, to operate as set forth.

OHANOY H. LATHROP.

Witnesses MICHAEL RYAN, FRED. HAYNEs.

The inclined inner surfaces or cam- 

